At high temperatures, carbon-based materials are known to exhibit ferromagnetic properties. More recently, carbon-based materials have been shown to exhibit ferromagnetism (FM) at room temperatures. More specifically, recent experiments have shown that absorbed atoms/molecules can trigger room temperature ferromagnetism in carbon structures. However, whether this ferromagnetic behavior is intrinsic to the carbon-based materials, or extrinsic (e.g., caused by metallic impurities) is not fully understood.